MDRD is a multicentered cooperative study designed to ascertain whether dietary protein restriction favorably influences the rate of progression of chronic renal diseases of diverse etiology. Specific protocols serve 1) to compare the efficacy of a low protein diet and phosphorus restriction, a diet very low in protein and phosphorus but with nitrogen supplements, and a diet of moderate protein and phosphorus intake on the course of progressive chronic renal disease; 2) to determine patient acceptance of the dietary intervention; and 3) to evaluate the safety and nutritional and other effects of these dietary interventions. Phase 11, a test of the operations manual and BWH performance in carrying out the proposed study is nearing completion. The present proposal, seeking support for BWH to participate in Phase III of this study, contains an interim Phase II Summary and future Phase III plans for local recruitment and patient randomization efforts, details of present and future protocol adherence and implementation, facilities and resources and aspects of clinic organization and present/future management. Optimal new physical facilities will be made available on 7/1/87 to accommodate all personnel and patient activities related to this study. These facilities will remain available through the completion of the study. Based on a strongly positive site-visit performance report and a major commitment to participate responsibly and effectively in Phase III, BWH remains extremely enthusiastic about the longterm contributions to medical practice certain to emerge from this landmark collaborative clinical trial.